Control techniques used in virtual machines such as Java programs have permeated various fields of technology such as communications and broadcasting. In the field of broadcasting in particular, techniques have already been established for having Java applications operate in accordance with playback of digital video, and various services associated with menu control by Java applications are gathering the interest of viewers.
As a further development from the field of broadcasting, various ways of realizing playback control of disc contents are presently being investigated. Disc contents are not played according to simple progression along one playback time axis, but by a complicated progression in which branches from one playback axis to another playback axis are possible. Such branching of disc contents occurs in units of a Title. A Title has at least one playback time axis, and start and end points of an application or applications are defined on the time axis of the Title. When applications operate along the time axis of a particular Title, various procedures must be performed when a branch from one Title to another occurs, such as terminating all currently running applications, and then re-running applications. Here, “Title boundary” is used to refer to the interval from one Title ending to the next Title starting. When it is necessary to run and terminate a relatively large number of applications, this Title boundary period becomes extra ordinarily long, and a considerable time passes before the Title that has been branched to starts.